About “ntoskrnl.exe is missing or corrupt”

The following information on this error has been compiled by NeoSmart Technologies, based on the information gathered and reported by our global network of engineers, developers, and technicians or partner organizations.

Description and Symptoms

The error messages, alerts, warnings, and symptoms below are tied to this error.

Symptom 1: ntoskrnl.exe is missing or corrupt error screen on startup

The ntoskrnl.exe (short for Windows NT operating system kernel) is responsible for various system services such as hardware virtualization, process and memory management. Right after NTLDR and NTDETECT boot files are done with the basic loading subroutines and hardware detection, the control over the boot process is passed to ntoskrnl.exe so that the operating system could start loading. However, if ntoskrnl.exe is missing or corrupt, then the following error appears and the boot process is halted.

Windows could not start because the following file is missing or corrupt:
<Windows root>\system32\ntoskrnl.exe.
Please re-install a copy of the above file.

Causes of this Error

This error has been known to occur as a result of one or more of the following:

Cause 1: Invalid boot.ini configuration

An incorrectly configured boot.ini file may result in the Windows XP bootloader attempting to load Windows from the wrong drive or partition.

If NTLDR attempts to load Windows from the wrong partition, it will not find ntoskrnl.exe and this error may be occur.

Boot.ini may become misconfigured as a result of incorrectly installed software, a failed Windows update, virus infection, or an incomplete Windows upgrade.

Cause 2: Corrupt boot volume

Corruption of the boot partition on a Windows XP PC can cause this error to be present.

The boot drive can become corrupted as a result of an unsafe shutdown, sudden power loss, unsafe removal of a local or external disk, or physical disk damage and/or corruption.

A corrupted boot partition may occur on both NTFS and FAT32 filesystems and volumes.

Cause 3: Corrupted or deleted ntoskrnl.exe

As the error screen states, this error is sometimes caused by a lost or corrupted ntoskrnl.exe file on the Windows system partition. The system partition may or may not be the same as the boot partition (see above).

\Windows\system32\ntoskrnl.exe may be deleted or corrupted as a result of unsafe shutdown, NTFS or FAT32 volume corruption, failed Windows updates, or virus infection.

Cause 4: PS/2 keyboard incorrect behaviour

Keyboard-related software issues are largely no longer a concern with newer USB/internal keyboards. However, older PCs that use a keyboard attached to the PC via a serial interface, could misinterpret the device’s mapped memory as a storage volume, leading to boot problems like this one.

Cause 5: Missing drivers for hard disk controller

If Windows does not have the necessary drivers to access the Windows system files on the main partition, this error message can be seen. This can happen as a result of a failed driver update, changes to the hardware configuration, or changes to the hard disk configuration in the BIOS.

Fix NTOSKRNL.exe is missing or corrupt in Windows

Fix #1: Use Easy Recovery Essentials

Easy Recovery Essentials is guaranteed to fix the “NTOSKRNL.EXE is missing or corrupt” error automatically using its built-in Automated Repair option. EasyRE is currently available for Windows XP, Vista, 7 and 8 and can be downloaded and created on any PC.

Once EasyRE is running, choose the “Automated Repair” option and click Continue.

Choose “Automated Repair” in Easy Recovery Essentials

After EasyRE scans your computer’s drives, identify and select the drive letter for your Windows installation from the list, and then click on the Automated Repair button to begin.

Choose the drive associated with the Windows installation you’re trying to repair.

Easy Recovery Essentials will start analyzing the selected drive for problems. EasyRE will test for and attempt to automatically correct errors with the disk, partition, bootsector, filesystem, bootloader, and registry. No intervention is required, as EasyRE’s repair is fully automated:

Fix #2: Replace or recreate a corrupted/incorrect boot.ini

A boot.ini file is used by Windows to configure and display its operating system options. Instructions on manually recreating the boot.ini file are also available, but require a moderate level of computer expertise. The instructions below will guide you on recreating boot.ini automatically from the Windows XP setup CD.

You are being asked to provide a name to be assigned and shown in the boot menu for the installation you picked in the previous step. Examples:

Enter Load Identifier: Windows XP Professional (Recovered)

(Optional) When you receive a message like this:

Enter OS Load options

Type in /fastdetect followed by Enter

Restart your computer.

Here is an example of what the PC’s console output should look like once the boot.ini file is restored:

Restoring Boot.ini file

Fix #3: Boot into Last Known Good Configuration

Windows Setup CD/DVD Required!Some of the solutions below require the use of the Microsoft Windows setup CD or DVD. If your PC did not come with a Windows installation disc or if you no longer have your Windows setup media, you can use Easy Recovery Essentials for Windows instead. EasyRE will automatically find and fix many problems, and can also be used to solve this problem with the directions below.

Rebooting your PC into “Last Known Good Configuration” mode forces your computer to use a saved version of the Windows registry that was in place the last time your computer successfully booted. If this error is being caused as a result of incorrect, misconfigured, or uninstalled drivers, booting your PC in “last known good configuration” mode may resolve the problem. This option is available from the Advanced Boot Options menu at system start.

Wait for your BIOS to complete POST (the screen with your manufacturer logo and/or system information)

Quickly begin tapping F8 repeatedly, until you see the list of boot options

Choose “Last Known Good Configuration (Advanced)”

Press Enter and wait for your PC to boot.

Fix #4: Disconnect PS/2 or serial keyboard

If the fix above doesn’t work and the PC is using an old PS/2 keyboard, it’s recommended to attempt disconnecting it and then restarting the computer to see if anything changes. Here are the steps to do it:

Shutdown the computer

Disconnect the keyboard

Power up the computer

Some users have reported that that the NTOSKRNL.exe error disappears after disconnecting the keyboard and then reconnecting it after a restart.

Fix #5: Restore the ntoskrnl.exe file

If ntoskrnl.exe is in fact missing or corrupt, you can restore the original ntoskrnl.exe file back from your Windows XP installation disc.

Press any key to boot into the CD when you see the “Press any key to boot from CD” message.

Press R to start Recovery Console when the Options screen appears.

Type in your Administrator password followed by the Enter key to submit it.

You’ll reach the Command Prompt now, type the following command, where D:\ is your CD’s drive letter and C:\ is the letter of the drive you installed Windows to:

expand D:\i386\ntoskrnl.ex_ C:\Windows\system32\

Press Y when you are asked if you want to overwrite this file and then hit Enter to submit the command.

Restart your computer.

Here is an example of what the PC’s console output should look like once the ntoskrnl.exe file is restored:

Restoring the ntoskrnl.exe file

Fix #6: Run chkdsk

If this problem is being caused by a corrupt boot or system partition, it may be repaired by scanning the NTFS or FAT32 partition for errors or corruption. chkdsk will verify files and data on the disk.

Here are the steps:

Insert your Windows CD; restart your computer.

Boot into the CD by pressing any key when the “Press any key to boot from CD” message appears on your computer.

Press R to open the Recovery Console once at the Options menu.

Type in your Administrator password; hit Enter

At the command prompt, type in the following command and press Enter

chkdsk /r

After the chkdsk process is completed, restart your computer. Make note of any warnings or alerts that chkdsk prints.

Here is an example of what the PC’s console output should look like once the chkdsk.exe is complete:

Windows XP chkdsk result screen

More Information

Linked Entries

The errors below have been verified as being associated with or related to this problem: